SCOTTSDALE, Ariz. — The honeycomb returned to a white board in an office next to the Rockies’ clubhouse last week. Their manager calls it a molecular model. It is a map of every pitch they want to throw this season.

“We’re probably going to have another meeting about it tomorrow morning,” Colorado manager Bud Black said. “It’s a catcher’s chart. It’s a model that we use to help catchers with game-calling.”

The ongoing education of Colorado’s young catching corps continued again this spring with a new veteran backstop and a demanding manager leading the way. The Rockies signed Chris Iannetta to a two-year, $8.5 million deal in early December because Tony Wolters and Tom Murphy are not quite ready to take over a full season of responsibility.

The Rockies were not about to flirt with the risk of developing two young catchers on the fly in their drive to return to the postseason. But their tutelage is no less pressing. That’s why Black, a 15-year pitcher, spends so much of his time instructing his catchers with a firm hand.

On the white board in his office, written in erasable ink, is a bracket of every ball-strike count and its succeeding permutation. It starts 0-0. Then branches to 0-1 and 1-0, then 0-2, 1-1 and 2-0. And so on. Black quizzes his catchers on what pitch they should call in each count, for every pitcher on Colorado’s staff, against any hitter in the league.

“It’s like chess,” said Wolters, 25. Cleveland Indians manager Terry Francona converted him from a middle infielder to a catcher in the minor leagues in 2013 and came to catching late. His learning curve was stunted. Catching and game-calling takes a minute to learn and a lifetime to master.

“There aren’t right moves at any time,” Wolters said. “Just keep mixing. You’re not trying to trick anyone. But you’re trying to use your pitcher’s strengths and throw pitches that are low risk. You don’t want high-risk pitches in certain counts. There’s no science to it.”

Murphy, 24, debuted last season but played in just seven games. He broke his hand a year ago when he smacked into a bat trying to throw out a runner at second base. He swings a power bat, an enticing plus for a defense-first position. But his defense is also still developing.

The Rockies nearly went headlong into last season with two catchers who, combined, carried one year of major-league experience. It was a risk, to say the least, with four rookie starting pitchers about to break through. Former Colorado general manager Dan O’Down once said that young pitching paired with young catching is a recipe for disaster.

So Black and his staff pulled back the reins and general manager Jeff Bridich added two veterans, Jonathan Lucroy at the trade deadline and Ryan Hanigan late in spring training, to help carry the load. It worked. They helped guide an untested staff into the postseason.

Lucroy left for free agency and the Rockies instead signed Iannetta as their newest veteran game-caller. He debuted with the Rockies in 2006 but left after the 2011 season for Anaheim. His defense improved over time and the catcher who returned to Colorado is markedly better defensively than when he left.

“For a catcher, maybe you had a conversation with a pitcher that changed his mentality, and then he pitched a great game,” Iannetta said of a catcher’s responsibility. “Or another guy gets a hit in a certain situation, and maybe you helped the pitcher relax in a certain situation. You can’t put that on a stat sheet.”

Nearly every pitch in a Rockies game is called by the catcher, save for a few scripted sequences that Black will improvise between innings or on a visit to the mound. Their catchers are like quarterbacks, they need to determine the sequence of decisions.

“Hitting is hard. So I’m going with our pitcher’s strengths,” Wolters said, explaining his philosophy for pitch-calling. “Establish down and away, establish in, establish one off-speed pitch. Then keep bringing him in as we go.”

The white board chart is not universal. And the map changes by the day. Every pitcher is different and unlike even themselves from a previous start. Maybe their curveball hooks like a whip on Monday but flattens out on Saturday. The catcher must corral them in the moment.

“They’ve done a really good job getting to know us and how we work with certain pitches and how they want to manipulate that,” veteran right-hander Chad Bettis said of Wolters, Murphy and Colorado’s young catchers. “It’s all built off communication.”

Last month, the Rockies scheduled a series of sit-downs between every pitcher on the staff and their group of catchers, seven total in big-league camp. They took notes and grilled their pitchers with questions, like an interview or a casting call.

They need to learn when to throw a fastball inside in certain counts, for example. Or when to throw away. When to break out a backdoor breaking ball or when to get creative when they’re behind in the count. Usually getting tricky “might not be the most ideal thing,” Black said.

Once they learn pitchers, Wolters and Murphy can start to scout the hitters. Is he an early-count hitter? Does he swing inside-out? Is he a contact guy? Go hard up and in? Soft away? Does he sit soft, looking for breaking balls? Is he hunting fastballs? Everything, including the specific terminology, is important.

“Depends on the hitter. Now that I’m learning, I can really see it,” Wolters said. “You have to keep adapting and evolving.”

Colorado’s catchers have a lot going on. They have to answer to Black, their boss; their bench and catching coach, Mike Redmond; the pitching coaches; the hitting coach; 13 pitchers at a time. And themselves.

There is no headset for them to take instructions during a game. That’s why Black and his staff are trying to imprint the honeycomb-looking molecular model on their minds.

covers baseball and the Rockies and all sorts of sports. He started working at The Denver Post while in high school before graduating from the University of Colorado. Reach him at ngroke@denverpost.com

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